V-Belt pulley with automatic tensioning device

Abstract

An automatically adjustable V-belt pulley which has a moveable pulley half that is resiliently urged by a compression spring axially towards a fixed pulley half in order to vary the dimension of the V-belt receiving groove defined therebetween and to maintain a substantially constant tension on the V-belt as it expands during continued use. A restraining means is provided between the spring and moveable pulley half which only permits expansion of the spring and axial movement of said pulley half in one direction.

The embodiments of the invention in which an exclusive property of priviledge is claimed are defined as follows: 
     
       1. In a V-belt pulley having an automatic V-belt tensioning arrangement comprising a shaft, a first pulley half carried on the shaft, a compression spring resiliently urging the first pulley half axially along the shaft towards a second pulley half fixed to the shaft, key means drivingly connecting the pulley halves and a means between the spring and the first pulley half for permitting expansion of the spring and limiting the axial movement of the first pulley half to only one direction. 
     
     
       2. In a V-belt pulley according to claim 1 wherein the permitting and limiting means include an apertured disc sleeved over the shaft and conically deflected at the outer periphery against the first pulley half. 
     
     
       3. In a V-belt pulley according to claim 2 wherein the apertured disc has a plurality of radially extending fingers which are flexed in an axial direction away from the first pulley half and grip the shaft. 
     
     
       4. In a V-belt pulley according to claim 2 wherein the permitting and limiting means further include a first cup connected to the first pulley half, a second cup telescopically mounted over the fist cup, and means for connecting the second cup to the shaft, the spring extending between the bottoms of the cups, and the apertured disc being interposed between the bottom of the first cup and the adjacent end of the spring. 
     
     
       5. In a V-belt pulley according to claim 2 wherein the key means include a tab extending outwardly from one of the pulley halves which passes through an opening provided in the other pulley half. 
     
     
       6. In a V-belt according to claim 5 wherein the permitting and limiting means further include a first cup connected to the first pulley half, a second cup telescopically mounted over the first cup, and means for connecting the second cup to the shaft, the spring extending between the bottoms of the cups, and the apertured disc being interposed between the base of the first cup and the adjacent end of the spring; 
     
     
       7. In a V-belt pulley according to claim 6 wherein the apertured disc has a plurality of radially extending fingers which are flexed in an axial direction away from the first pulley half and grip the shaft.